Problems with Auto focus (1 Viewer)

I have been doing photography for 20 years with manual focus cameras, only started using AF SLR on September 2008, and now almost a year i have three major problems:

1- How to focus on a moving subject, i am not speaking of a kind of predicted movments like a flying gull towards or away from the photographer, the C-AF mode can deal with it nicely and perfectly if the the photographer have enough experience, i am referring to the kind of movement that comes from the wind, like when a bird on a top of a branch with moderate strength wind, how to deal with that, what i do i switch to MF and always works fine.

http://www.birdforum.net/gallery/showphoto.php/photo/261100/ppuser/71763

http://www.birdforum.net/gallery/showphoto.php/photo/261774/ppuser/71763

2- In case of macros, like shooting flowers that are constantly moving with surface winds and breeze, even if you turn into C-AF and put on the image stabilization mode, the release button would not be pressed as the image is out-of-focus, so what i do is also turn to MF and works for me fine.


3- when shooting faint subjects on the infinity distance like the morning moon, you will not be able to focus unless you use MF.

http://www.birdforum.net/gallery/showphoto.php/photo/262265/ppuser/71763

in general i don't get successful focus for infinity objects with AF

There is another thing which i use to do with MF lenses that seems to be impossible with AF lenses, is when you want to take a picture without looking on the viewfinder as you don't want to rise the camera to your eyes, i used to set the focusing ring on the estimated distant and release the button and have good results. but this is a very special situation, not as common as the ones i stated before.

I know these problems could have been due to my lack of experience with AF, i was just thinking if there is a function of locking the focus, but it would make shooting slower. Frankly i find shooting with AF much slower than MF, and i am not comparing to the manual focus on the AF lenses these are far less reliable and accurate as the ones on the older all MF lenses.

Dulce, You have somehow removed the exif from the second image. I feel sure that it was taken at too slow a speed ? May I suggest that you use Av ? That way you get the highest possible speed from the camera, depending on the ISO you have set obviously.
I have just tried the exif on all of the images and it doesn`t seem to be there ? Tell a lie ! In the last pic there is exif.....hoorah ! However the exif says that you took the pic at f 7.1 which I would have thought was inappropriate ? I would have thought that the pic would require a lot longer exposure than that ?

Hi John, my vucablaly in digital trminolgy is a bit limited, can you tell me what do you maen by exif, so that i can understand what you mean.

However in the first picture the shutter speed was high i was shooting at around 11 am in a summer day in Jeddah, and as i was in a shady place i sat the ASA on 400 for the possibility on getting of taking a shot for a bird on the ground. I did not record it but sure it is 1/500 or more.

ammadoux said:

I have been doing photography for 20 years with manual focus cameras, only started using AF SLR on September 2008, and now almost a year i have three major problems:

1- How to focus on a moving subject, i am not speaking of a kind of predicted movments like a flying gull towards or away from the photographer, the C-AF mode can deal with it nicely and perfectly if the the photographer have enough experience, i am referring to the kind of movement that comes from the wind, like when a bird on a top of a branch with moderate strength wind, how to deal with that, what i do i switch to MF and always works fine.

http://www.birdforum.net/gallery/showphoto.php/photo/261100/ppuser/71763

http://www.birdforum.net/gallery/showphoto.php/photo/261774/ppuser/71763

Click to expand...

Being an FD lens shooter I'm always the first to scream Manual focus for all things photographic but....I do understand manual focus is not for everyone.

What I believe your problem here is Continus Focus is just not fast enough to compensate for these conditions.

However, in the case of the first shot I have to honestly say that JohnZ hit the nail on the head, The Silverbill shows little to no movement, yes it's a slight missfocus but it's within what I would call acceptable tolerance for my own shots, the bulk of the issues with that Photo come in the Bokeh and the moving tree exadgerating the impression of OoF.

ammadoux said:

2- In case of macros, like shooting flowers that are constantly moving with surface winds and breeze, even if you turn into C-AF and put on the image stabilization mode, the release button would not be pressed as the image is out-of-focus, so what i do is also turn to MF and works for me fine.

Click to expand...

Sorry, but when it comes to Macro photography, Manual Focus is really the only way to do it. A good majority of macro work involves longer shutter speeds due to a few different factors, One big one is the slow nature of macro lenses and razor thin Depth of Field, this causes confusion to any AF in any camera. Further more, as with any lens the amount of magnification will amplify any and all movement...this is something that has no simple solution.

You have given ample praize to the birds I've posted in my BF allery I feel obligated to show you these images as they are what this section is reffering to so you can safely say you know what I can do in this field.

http://www.photo-lucidity.com/pic-1740.html

http://www.photo-lucidity.com/pic-1738.html

http://www.photo-lucidity.com/pic-1737.html

Your best results will come with amanual focus, tripod, mirror lock, small apertures and windless day

ammadoux said:

3- when shooting faint subjects on the infinity distance like the morning moon, you will not be able to focus unless you use MF.

http://www.birdforum.net/gallery/showphoto.php/photo/262265/ppuser/71763

in general i don't get successful focus for infinity objects with AF

Click to expand...

I have no answer for this, I have read many complaints about modern glass either not having infinate or just failing at it with AF, this is one issue you do not seem to be alone on.

ammadoux said:

There is another thing which i use to do with MF lenses that seems to be impossible with AF lenses, is when you want to take a picture without looking on the viewfinder as you don't want to rise the camera to your eyes, i used to set the focusing ring on the estimated distant and release the button and have good results. but this is a very special situation, not as common as the ones i stated before.

I know these problems could have been due to my lack of experience with AF, i was just thinking if there is a function of locking the focus, but it would make shooting slower. Frankly i find shooting with AF much slower than MF, and i am not comparing to the manual focus on the AF lenses these are far less reliable and accurate as the ones on the older all MF lenses.

Click to expand...

Experience is only going to teach you how to work with the limitations of the lens in the exact same way it did twenty years ago. Your best bet is to work with the manor that is most comfortable and least interfering for you the shooting photographer. Some times the companies creature comforts are not the most comfortable for the individual creature.

ammadoux said:

Hi John, my vucablaly in digital trminolgy is a bit limited, can you tell me what do you maen by exif, so that i can understand what you mean.

Click to expand...

Exif information is information the camera embeds into the image file telling what camera, shutter speed, aperture and a few other details about the photo.

As Battou has explained if you use "Save" instead of "Save for web" then the exif will remain in the image. That enables folks to see what speed etc., the shot was taken at.
It then gives them an idea of whether you have taken the pic at an unreasonably low speed. What lens are you using ?
Hope this helps.

thanks Battou for your reply, it is really comforting to read it from a real professional like your good self. Guess the whole problem is that i am so used to MF and it will take me a while and maybe a long time to adjust with AF. i will bw glad to visit your web site and register i will do it shortly.

thanks also JohnZ for your kind help.